Digit button-operated air compressor output control structure

ABSTRACT

A digit button-operated air compressor output control structure for controlling output of compressed air from an air compressor by means of a digital control panel and an air pressure regulating structure with internal pressure sensors for enabling the user to set the desired output air pressure quickly and to control the output air pressure stably.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to air compressors and more particularly, to a digit button-operated air compressor output control structure.

2. Description of the Related Art

FIG. 1 illustrates a regular air compressor 1, which comprises a shielding shell 2 and a tank 3. The shielding shell 2 has mounted therein parts for generating compressed air such as motor, fan, and etc. The tank 3 is for accumulation of compressed air. When using the air compressor 1, the air outlet 4 of the air compressor 1 is connected to an external air tool (not shown) so that compressed air goes out of the air compressor 1 through the air outlet 4 to the external air tool for driving a movable part of the external air tool. The air compressor 1 has a control knob 5 for regulating the pressure of air that goes out of the air outlet 4, and a pressure meter 6 connected between the control knob 5 and the air outlet 4 for measuring the pressure of output air. The use of this structure of air compressor has drawbacks. When regulating the output pressure, the user must operate the control knob 5 and at the same time watch the indication of the pressure meter 6 till the accurate output pressure is in presence. The user shall have to spend a lot of time in regulating the desired output pressure. Further, because the control knob 5 is exposed to the outside of the shielding shell 2, it may be rotated or hit by a nearby worker accidentally, causing damage to the air tool or injury to workers.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a digit button-operated air compressor output control structure, which controls the output of compressed air from an air compressor by means of a digital control panel and an air pressure regulating structure so that the user can set the desired output air pressure quickly and control the output air pressure stably.

It is another object of the present invention to provide a digit button-operated air compressor output control structure, which is equipped with pressure sensors for accurate air pressure output control.

To achieve these and other objects of the present invention, the digit button-operated air compressor output control structure is for controlling output of compressed air from an air compressor, comprising a main body, an exhaust valve, an intake valve assembly, a first pressure sensor, a second pressure sensor, and a control panel. The main body is fixedly fastened to the air compressor, comprising an air inlet connected to the air compressor for guiding in compressed air from the air compressor, an air outlet for guiding out compressed air, a main air chamber, a first air passage in communication between the air inlet and the main air chamber, and a second air passage in communication between the air inlet and the main air chamber. The exhaust valve is movable in the main air chamber and divides the main air chamber into a first air chamber and a second air chamber. The first air chamber is in communication with the first air passage and the air outlet. The second air chamber is in communication with the second air passage. The intake valve assembly is mounted in the second air passage, and adapted to regulate the flow rate of compressed air from the air compressor into the second air chamber. The first pressure sensor is mounted in the second air passage between the air inlet and the intake valve assembly, and adapted to detect the air pressure in the second air passage and to output a first signal indicative of the detected air pressure. The second pressure sensor is mounted in between the intake valve assembly and the second air chamber, and adapted to detect the air pressure in between the intake valve assembly and the second air chamber and to output a second signal indicative of the detected air pressure. The control panel comprises a circuit board electrically connected to the intake valve assembly and the first pressure sensor and the second pressure sensor and adapted to convert the first signal from the first pressure sensor and the second signal from the second pressure sensor into respective digital signals for display through display screen means, a set of digit control keys electrically connected to the circuit board for setting the control of the intake valve assembly in regulating the flow rate of compressed air from the air compressor into the second receiving chamber, and display screen means electrically connected to the circuit board for displaying the digital signals produced by the circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a conventional air compressor.

FIG. 2 is an elevational view of a digit button-operated air compressor output control structure in accordance with the present invention.

FIG. 3 is an exploded view of the digit button-operated air compressor output control structure in accordance with the present invention.

FIG. 4 is a schematic side view of a part of the present invention, showing the structure of the connecting member of the main body.

FIG. 5 is a schematic side view of a part of the present invention, showing the arrangement of the control panel and the flow guide.

FIG. 6 is a schematic bottom view of a part of the present invention, showing the arrangement of the flow guide and the control panel.

FIG. 7 is a schematic bottom view of a part of the present invention, showing the arrangement of the flow guide and the valve holder.

FIG. 8 is a schematic drawing of a part of the present invention, showing the flowing direction of compressed air in the flow guide and the connecting member.

FIG. 9 is a schematic sectional view of a part of the present invention, showing the arrangement of the first regulating valve and the second regulating valve in the valve holder.

FIG. 10 is a top view of the touch panel according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 2-10, a digit button-operated air compressor output control structure 10 in accordance with the present invention is connected between an air compressor (not shown) and an air tool (not shown) for controlling output of compressed air from the air compressor to the air tool. The digit button-operated air compressor output control structure 10 comprises a main body 12, an exhaust valve 14, an intake valve assembly 16, a control panel 18, a first pressure sensor 20, and a second pressure sensor 22.

The main body 12 is comprised of a connecting member 121 and a flow guide 122. The connecting member 121 is fastened to one side of the flow guide 122. The connecting member 121 and the flow guide 122 are affixed to the air compressor.

The connecting member 121 is formed of a manifold, having an air inlet 121 a, an air outlet 121 b, and a first groove 121 c. The groove 121 c is formed on one side of the connecting member 121 that is fixedly fastened to the flow guide 122 (see FIG. 4). The air inlet 121 a is in communication with a first main air passage Al and a first sub air passage A2 that are defined inside the connecting member 121. The first main air passage A1 is in communication with the first groove 121 c. The first sub air passage A2 is in communication with the first main air passage Al and the flow guide 122. The internal compressed air of the air compressor goes through the first main air passage A1 into the first groove 121 c and then through the first sub air passage A2 into the flow guide 122. The air outlet 121 b is in communication with the first groove 121 c for guiding compressed air from the first groove 121 c to the air tool.

The flow guide 122 has a second groove 122 a formed on its one side corresponding to the first groove 121 c, as shown in FIG. 6, a front air passage A3, a third groove 122 b and an opening 122 c on its back side, and a first receiving hole 122 d and a second receiving hole 122 e formed on the front side and disposed in communication with the third groove 122 b and the second groove 122 a respectively. The front air passage A3 is in communication with the first sub air passage A2 of the connecting member 121 and the third groove 122 b of the flow guide 122 for guiding compressed air out of the connecting member 121 into the flow guide 122. The opening 122 c is formed on the peripheral wall of the second groove 122 a. The first receiving hole 122 d and the second receiving hole 122 e accommodate the first pressure sensor 20 and the second pressure sensor 22 respectively.

The exhaust valve 14 is comprised of a plunger 141, a valve sleeve 142, a valve plug 143, and an elastic member 144. As shown in FIG. 8, the plunger 141 is mounted in the first groove 121 c, defining with the first groove 121 c a first receiving chamber 12 a and also defining with the second groove 122 a a second receiving chamber 12 b. The first receiving chamber 12 a and the second receiving chamber 12 b constitute a chamber 123. When the air pressure in the first receiving chamber 12 a and the air pressure in the second receiving chamber 12 b are not equal, the plunger 141 will be moved in the first receiving chamber 12 a. Further, the plunger 141 has a pin 141 a inserted into the first receiving chamber 12 a. The valve sleeve 142 has a small diameter section 142 a, a big diameter section 1242 b, and an axial hole 142 c. The small diameter section 142 a is set in the junction between the first groove 121 c and the first main air passage A1. The small diameter section 142 a has two side holes 142 d in communication with the axial hole 142 c. The big diameter section 142 b has radial grooves 142 e. The side holes 142 d, the axial hole 142 and the radial grooves 142 e constitute an exhaust air passage A4, as shown in FIG. 4, for guiding compressed air from the first main air passage A1 through the exhaust air passage A4 into the first receiving chamber 12 a and then out of the air outlet 121 b. The valve plug 143 is a rubber member inserted into the axial hole 142 c to seal the two side holes 142 d. The elastic member 144 according to this embodiment is a spring, having one end stopped against the inside wall of the connecting member 121 and the other end stopped against the valve plug 143. Therefore, the elastic member 144 supports the valve plug 143 in the position where the valve plug 143 seals the side holes 142 d to block the exhaust air passage A4. When the plunger 141 is forced by compressed air to move toward the valve sleeve 142, the pin 141 a of the plunger 141 is inserted into the axial hole 142 c to push the valve plug 143 away from the side holes 142 d, thereby opening the exhaust air passage A4.

The intake valve assembly 16 is affixed to the back side of the flow guide 122, which is provided with the third groove 122 b and the opening 122 c. The intake valve assembly 16 is comprised of a valve holder 161, a first regulating valve 162, and a second regulating valve 163. The first regulating valve 162 and the second regulating valve 163 according to this embodiment are electromagnetic valves.

As shown in FIGS. 7-9, the valve holder 161 is fixedly connected to the flow guide 122, having a first air chamber 161 a, a second air chamber 161 b, a first through hole 161 c in communication between the first air chamber 161 a and the third groove 122 b (see FIG. 7), and a second through hole 161 d in communication between the first air chamber 161 a and the opening 122 c. The first air chamber 161 a constitutes with the first through hole 161 c and the second through hole 161 d a middle air passage A5. As shown in FIG. 7, the middle air passage A5 is in communication with the third groove 122 b and the opening 122 c. As shown in FIG. 8, the first sub air passage A2 and the front air passage A3 constitute with the middle air passage A5 a second air passage A6. The second air passage A6 is in communication with the air inlet 121 a and the second receiving chamber 12 b. The valve holder 161 further has a third through hole 161 e in communication between the second air chamber 161 b and the opening 122 c, and a fourth through hole 161 f in communication between the second air chamber 161 b and the outside space. The flowing direction of compressed air among the aforesaid component parts will be described further.

As shown in FIG. 9, the first regulating valve 162 is fixedly fastened to the valve holder 161 and electrically connected to the control panel 18 by an electric circuit (not shown). The first regulating valve 161 has a first stop member 162 a corresponding to the first air chamber 161 a. The first stop member 162 a is movable in the first air chamber 161 a subject to the control of the control panel 18, thereby changing the volume of the first air chamber 161 a to regulate the flow rate of compressed air that goes out of the first air chamber 161 a through the second through hole 161 d and the opening 122 a into the second receiving chamber 12 b.

The second regulating valve 163 is fixedly fastened to the valve holder 161 and electrically connected to the control panel 18 by an electric circuit (not shown). The second regulating valve 163 has a second stop member 163 a corresponding to the second air chamber 161 b. The second stop member 163 a is movable in the second air chamber 161 b subject to the control of the control panel 18, thereby changing the volume of the second air chamber 161 b to regulate the flow rate of compressed air that goes out of the second air chamber 161 b through the fourth through hole 161 f to the outside.

As shown in FIG. 3, the control panel 18 is fixedly mounted on one side of the flow guide 122, comprised of a circuit board 181 and a touch panel 182.

The circuit board 181 carries the first pressure sensor 20 and the second pressure sensor 22 on its one side facing the flow guide 122. As shown in FIG. 6, the first pressure sensor 20 is inserted through the first receiving hole 122 d into the third groove 122 b to detect air pressure in the front air passage A3, and to output a first signal to the circuit board 181 indicative of the detected air pressure. The second pressure sensor 22 is inserted through the second receiving hole 122 e into the second groove 122 a to detect air pressure in the second receiving chamber 12 b, and to output a second signal to the circuit board 181 indicative of the detected air pressure. Further, a battery 24 is electrically connected to the circuit board 181 to work as standby power supply for the circuit board 181. The circuit board 181 further has mounted on its one side that is bonded to the touch panel 182 a display screen 181 a, a set of digit control key switches 181 b, four first light sources 181 c, a unit switching key 181 d, an enter key 181 e, a clear key 181 f, a safety key 181 g, and a second light source 181 h. The display screen 181 a has its upper part for indicating the air pressure detected by the first pressure sensor 20, and its lower part for indicating the air pressure detected by the second pressure sensor 22. The functions of the other keys and light sources of the circuit board 181 will be described with the touch panel 182 hereinafter.

The touch panel 182 according to this embodiment is a plastic membrane. As shown in FIG. 10, the touch panel 182 is bonded to the side of the circuit board 181 carrying the digit control key switches 181 b, having a window 182 a corresponding to the display screen 181 a, a set of digits 182 b corresponding to the digit control key switches 181 b, the signs of “PSI” 182 c, “BAR” 182 d, “KPA” 182 e and “KGP” 182 f corresponding to the four first light sources 181 c, the sign of “BAT” 182 g corresponding to the second light source 181 h, the sign of “Unit” 182 h corresponding to the unit switching key 181 d, the sign of “Enter” 182 i corresponding to the enter key 181 e, the sign of “C” 182 j corresponding to the clear key 181 f, and the sigh of “Luck” corresponding to the safety key 181 g. By means of touching the touch panel 182, the user can switch the respective keys of the circuit board 181.

The digit control key switches 181 b allow the user to set the output air pressure of the air compressor to the air tool. After setting of the desired output air pressure, press the sign of “Enter” 182 i to drive the circuit board 181, causing the circuit board 181 to control the position of the first stop member 162 a of the first regulating valve 162. Further, when wishing to change the setting of the desired output air pressure, press the sign “C” 182 j to switch the clear key 181 f, thereby zeroing the reading in the lower part of the display screen 181 a for resetting. Further, clicking the sign of “Unit” 182 h each time, one of the first light sources 181 c is switched on and the other first light sources 181 c are switched off, indicating the corresponding sigh on the touch panel 182. For example, when the first light source 181 c corresponding to the sign of “PSI” 182 c is switched on, the reading shown in the window 182 a is based on the air pressure unit PSI. When pressing the sign “Luck” 182 k, the unit switching key 181 d, the enter key 181 e, the clear key 181 f, and the digit control key switches 181 b are switched between the enable mode and the disable mode, preventing triggering the touch panel 182 accidentally. Further, when the power level of the battery 24 drops below a predetermined value, the second light source 181 h is switched on to light up the sign “BAT” 182 g, advising the user to replace battery.

After understanding of the component parts of the digit button-operated air compressor output control structure 10 and their relationship, the operation of the present invention is described hereinafter.

If the user does not set the output air pressure, the first stop member 162 a of the first regulating valve 162 is stopped at the second through hole 161 d of the valve holder 161, blocking compressed air in the third groove 122 b and prohibiting compressed air from entering the second receiving chamber 12 b, and therefore the first pressure sensor 20 detects the tank pressure of the air compressor and outputs a corresponding first signal to the circuit board 181. The circuit board 181 converts the first signal into a digital signal for output through the upper part of the display screen 181 a. At the same time, the second pressure sensor 22 detects the air pressure of the second receiving chamber 12 b and outputs a corresponding second signal to the circuit board 181. The circuit board 181 converts the second signal into a digital signal for output through the lower part of the display screen 181 a. Because no compressed air goes into the second receiving chamber 12 b at this time, the indication on the lower part of the display screen 181 a remains unchanged.

When the user operated the digit control key switches 181 b and pressed the sign “Enter” 182 i as shown in FIG. 9, the circuit board 181 is driven to move the first stop member 162 a relative to the second through hole 161 d to change the volume of the first air chamber 161 a, regulating the flow rate of compressed air into the second receiving chamber 12 b subject to the set output air pressure. At this time, the plunger 141 is moved by compressed air to change the volume of the first receiving chamber 12 b, and the pin 141 a of the plunger 141 pushes the valve plug 143 away from the side holes 142 d of the valve sleeve 142 against the elastic member 144 to open the exhaust air passage A4, allowing compressed air to go from the first air passage A1 out of the exhaust air passage A4. Thus, the user can start other works immediately after setting of the desired output air pressure, saving much time and labor. Further, the safety key design of the touch panel prevents an accidental triggering. When compared to the conventional control knob design, the invention is safe in use.

Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. 

1. A digit button-operated air compressor output control structure for controlling output of compressed air from an air compressor, comprising: a main body fixedly fastened to said air compressor, said main body comprising an air inlet connected to said air compressor for guiding in compressed air from said air compressor, an air outlet for guiding out compressed air, a main air chamber, a first air passage in communication between said air inlet and said main air chamber, and a second air passage in communication between said air inlet and said main air chamber; an exhaust valve movable in said main air chamber and dividing said main air chamber into a first air chamber and a second air chamber, said first air chamber being in communication with said first air passage and said air outlet, said second air chamber being in communication with said second air passage; an intake valve assembly mounted in said second air passage and adapted to regulate the flow rate of compressed air from said air compressor into said second air chamber; a first pressure sensor mounted in said second air passage between said air inlet and said intake valve assembly and adapted to detect the air pressure in said second air passage and to output a first signal indicative of the detected air pressure; a second pressure sensor mounted in between said intake valve assembly and said second air chamber and adapted to detect the air pressure in between said intake valve assembly and said second air chamber and to output a second signal indicative of the detected air pressure; and a control panel, said control panel comprising a circuit board electrically connected to said intake valve assembly and said first pressure sensor and said second pressure sensor and adapted to convert said first signal from said first pressure sensor and said second signal from said second pressure sensor into respective digital signals for display through display screen means, a set of digit control keys installed in one side of said circuit board and electrically connected to said circuit board for setting the control of said intake valve assembly in regulating the flow rate of compressed air from said air compressor into said second receiving chamber, and display screen means electrically connected to said circuit board for displaying the digital signals produced by said circuit board.
 2. The digit button-operated air compressor output control structure as claimed in claim 1, wherein said main body comprises a connecting member and a flow guide, said connecting member comprising said air inlet, said air outlet, said first air passage, a sub air passage in communication with said first air passage, a first side, a first groove formed on said first side to accommodate said exhaust valve and to define with said exhaust valve said first receiving chamber, said flow guide being fixedly connected to the first side of said connecting member said flow guide, said flow guide comprising a second groove, which accommodates said exhaust valve and defines with said exhaust valve said second receiving chamber, a third groove, a front air passage in communication with said sub air passage and said third groove, an opening on one side of said second groove; said intake valve assembly is mounted in said third groove and one side of said opening, comprising a middle air passage in communication with said third groove and said opening, said middle air passage forming with said sub air passage and said front air passage said second air passage; said control panel is fixedly connected to said flow guide; said first pressure sensor is mounted in said third groove; said second pressure sensor is mounted in said second groove.
 3. The digit button-operated air compressor output control structure as claimed in claim 2, wherein said exhaust valve comprises: a valve plunger mounted in said first groove to separate said first receiving chamber and said second receiving chamber, said plunger having a pin inserted into said first receiving chamber; a valve sleeve fixedly connected to said connecting member of said main body, said valve sleeve having an axial hole for receiving the pin of said valve plunger and an exhaust air passage in communication between said first receiving chamber and said air outlet; a valve plug inserted into the axial hole of said valve sleeve and adapted to block said exhaust air passage and movable by said pin of said valve plunger to open said exhaust air passage; and an elastic member stopped between an inside wall of said connecting member and one end of said valve plug to support said valve plug in the position where said valve plug blocks said exhaust air passage.
 4. The digit button-operated air compressor output control structure as claimed in claim 2, wherein said intake valve assembly comprises: a valve holder fixedly connected to said flow guide, said valve holder comprising a first chamber, a first through hole in communication with said first chamber and said third groove, a second through hole in communication with said first chamber and said opening of said main body, said first chamber forming with said first through hole and said second through hole said middle air passage; and a first regulating valve installed in said valve holder and electrically connected to said circuit board, said first regulating valve having a first stop member controllable by said circuit board to move in said first chamber.
 5. The digit button-operated air compressor output control structure as claimed in claim 4, wherein said valve holder of said intake valve assembly further comprises a second chamber, a third through hole in communication with said opening of said main body and said second chamber, a fourth through hole in communication with said second chamber and the outside space; said intake valve assembly further comprises a second regulating valve installed ins aid valve holder and electrically connected to said circuit board, said second regulating valve having a second stop member controllable by said circuit board to move in said second chamber.
 6. The digit button-operated air compressor output control structure as claimed in claim 1, wherein said control panel further comprises a touch panel installed in the side of said circuit board carrying said digit control keys, said touch panel comprising a window corresponding to said display screen means, and a set of digits corresponding to said digit control keys.
 7. The digit button-operated air compressor output control structure as claimed in claim 1, further comprising a battery electrically connected to said circuit board. 